1. Field of Invention
The invention relates to methods of making window coverings of the type having a plurality of spaced apart slats, as in a venetian blind.
2. Description of the Related Art
Venetian type blinds are well-known and popular window coverings in which a plurality of slats are hung on ladders that extend between the headrail and a bottomrail. The ladders have two parallel rails connected by a series of equally spaced rungs on which the slats rest. The slats usually are metal, wood or plastic, but fabric slats have also been used. The rungs of the ladders in conventional venetian type blinds are not readily seen when the slats are in a horizontal open position. However, when the slats are tilted the rungs may be visible from one side or the other of the blind depending upon how the slats were tilted and whether or not they are obscured by the rails of the ladder.
U.S. Pat. No. 2,374,591 to Dunn discloses a venetian blind having metal slats. The longitudinal edges of the slats are rolled to form a U-shape. Notches are cut in the rolled edge to receive T-shaped clips crimped to tilt cords.
Sugiura in U.S. Pat. No. 1,851,782 discloses a venetian blind in which the slats are tubes of fabric stretched between two parallel rods. Spaced apart strips of material or tapes are secured to the longitudinal edges of the fabric slat. From the figures it appears that the tapes are sewn or glued to the slats. Movement of the tapes tilts the slats.
U.S. Pat. No. 6,105,657 to Zorbas discloses a fabric blind slat and a fabric Venetian blind assembly. The fabric blind slat includes an elongated strip of fabric. The strip of fabric has at least one longitudinally extending pocket on a longitudinal edge into which a relatively rigid support member is insertable. This design of fabric blind slat has drawbacks. Tilting the fabric blind slat moves the fabric body of the fabric blind slat in a manner that causes the upper part of the fabric blind slat to compress the lower part of the fabric blind slat, resulting in a wrinkle. In other words, supporting or stretching means must be provided so that the fabric body of the fabric blind slat can be maintained smooth under any operation status.
Another type of venetian type blind has a fabric sheet or fringe attached to one edge of each slat. This sheet or fringe extends to or below the adjacent slat. An example of this type of blind is disclosed in U.S. Pat. No. 3,388,490 to Kandel. In these blinds, the slats are supported on conventional ladders having parallel rails connected by a series of rungs of which the slats rest.
In United States published application US 2004/0103994 A1, I disclose a venetian type blind having fabric slats that does not utilize conventional ladders with rungs. Instead, I provide braided cords with spaced apart loops or clips that engage rods within the longitudinal pocket along opposite edges of each fabric slat. Consequently, the blind has no ladder rungs. Another advantage of this type of blind is that the blind can be readily assembled in accordance with the method here disclosed. That method can be used for blinds containing slats having pockets along opposite longitudinal edges, as well as blinds having such slats, and a screening flap attached to one or both longitudinal edges.